Deep breath, hold, release, deep breath, hold, release. Repeat as necessary to help with the stress and nervousness of this diagnosis.
What is your civie cat's name?
Operable is good. Make sure the vet gets clear margins when operating. Keeping you and your cat in our thoughts and hoping for all the best for your cat in surgery tomorrow and during the recovery process.
There are radiation treatments and chemotherapy treatments available to help treat this. Ask your vet if they think this would be appropriate for your cat. Not all cats are good candidates for these treatments. Explore your options is my best advice.
Squamous cell carcinoma (SCC) is unfortunately a very aggressive cancer. I've had 2 cats with oral squamous cell carcinoma and it was not operable in either case, since it was in their jaw. Radiation and chemo do not usually extend the life expectancy of cats with SCC. Sometimes other treatments can improve the quality of life, so you need to decide if that is something you still might want to try.
I opted for hospice care with my kitties. BUT, you need to decide what you think is right for you and your cat.